Row sums of a sum-of-powers triangle.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =17a(5) =40a(6) =106a(7) =316a(8) =1049a(9) =3830a(10) =15208a(11) =65072a(12) =297841a(13) =1449756a(14) =7468542a(15) =40555748a(16) =231335961a(17) =1381989882a(18) =8623700812a(19) =56078446616a(20) =379233142801